The invention relates to a device for sealing a bore hole and discharging drill cuttings and stripped excavation material, including a housing adapted to receive sealing elements and an opening capable of being connected to the bore hole, wherein one side wall of the housing is provided with at least one opening for the connection of a haulage duct and the housing end side facing the bore hole is equipped with a lockable, particularly screwable, sealing flange for the detachable connection with a bore hole lining.
Devices of the initially defined kind are used, for instance, for oil drill cuttings with a device of this type being described, for instance, in U.S. Pat. No. 4,529,210. The known devices are also denoted as blow-out preventors. However, when using same in the field of oil-drilling technology, large free spaces are usually accessible above the bore hole such that the known blow-out preventors can be relatively large-structured, having to offer a tight rotary mounting for the drill rod assembly in the first place. As a rule, the structural prerequisites of such preventors to be used in the field of oil-drilling technology, therefore, refer to the respective rotary mounting of a sealingly guided structural component which is itself designed as a coupling for the actuator of the drill rod assembly.
Devices of this type cannot be readily employed in critical drilling interventions by which a tunnel tube is made below ground and only the clear height of the tunnel tube is subsequently available as a free space, because of their dimensions, on the one hand, and because of their limited flexibility as regards the use of different elements, on the other hand. U.S. Pat. No. 5,380,127, for instance, describes a method for excavating minerals by means of a jet boring system that serves to work an ore deposit located below a lake. In that known method a tunnel tube is driven, after which, upon introduction of appropriate bores and linings, an excavation tool in the form of a liquid jet head is moved into the guiding tubes or lining tubes for the jet boring process and minerals are stripped off and carried away by the aid of high-pressure fluid and, in particular, high-pressure water. Such deposits, which call for extremely complex wallings, are to be found, for instance, in Canada, where the ore deposit would contain high concentrations of uranium ores with an accordingly high degree of contamination by radiation. Especially high demands are made on the safety and, in particular, sealing of such bores, and on top of this there is the risk in the event of natural lakes as are, for instance, found on top of such uranium ore deposits that water under high pressure might penetrate such bores and guiding tubes with a failure of the seal being likely to cause considerable contamination.